You can specify multiple source files for compression in two different ways:

• Specify source file(s) via File Connection Manager.
• Specify source file(s) via package variable.

The first option is a little bit tricky. If you provide an existing file with a wildcard specification, the dialog will not validate it. To make this work, create a File Connection Manager which points at the existing file. After you close the dialog, right-click on the just created connection manager and click the Properties menu. Set the ConnectionString property to the required wildcard specification. The Zip Task will now compress all files which match the specified wildcard.